Here at Marvellous Mushrooms, we’ve noticed a big rise in curiosity around mushroom grow kits - and we get it. Growing your own mushrooms at home is fun, sustainable, and honestly, a little bit magical.
But with that curiosity comes questions - and lots of them! So, we’ve pulled together the top 10 most common questions asked about mushroom grow kits, along with simple, clear answers to help you get started on your own homegrown fungi adventure.
Whether you're eyeing up a Lion’s Mane kit, considering an Oyster Mushroom grow kit, or just wondering if a grow kit is right for you, we’ve got you covered.
Are mushroom grow kits legal?
Yes, they are! Mushroom grow kits that feature legal, gourmet varieties - like Oyster Mushrooms, Lion’s Mane and Shiitake - are perfectly legal to buy and use in the UK.
It’s an easy mix-up with so-called “magic mushroom kits,” which are a whole different thing and contain psilocybin, a controlled substance, so are NOT legal.
But all of the species in our mushroom kits are completely legal, safe, and delicious. So if you’re dreaming of fresh Lion’s Mane on toast or a pan full of Pink Oysters, rest easy—you’re well within the law.
Are mushroom grow kits worth it?
Absolutely. For the price of a takeaway, you get the satisfaction of watching something grow, the freshness of gourmet mushrooms picked minutes before you eat them, and the joy of doing something a bit different.
Many of our customers say they’re amazed at just how much they get from a single kit. Not just mushrooms (though that’s a big win), but the experience itself: watching the first pins pop through, seeing them double in size overnight and then harvesting something you grew yourself! That’s the good stuff.
Plus, compared to supermarket mushrooms, the flavour of freshly grown Lion’s Mane or Oyster Mushrooms is next level.
Are mushroom grow kits safe?
Totally. When used properly, mushroom grow kits are safe for adults and kids alike. Our kits are carefully prepared in clean conditions and contain only the species listed on the label. You’re not going to accidentally grow anything toxic.
The key is following the care instructions - keep it clean, give it the right environment, and harvest when ready. If anything ever looks or smells off (rare, but it can happen), just reach out. We’re always happy to take a look and advise.
All this said it is worth noting that prolonged exposure to spores, if you worked on a mushroom farm for example, can lead to sensitivity in certain individuals. That's why we say that when you see spores being dropped you should harvest your mushrooms immediately.
Are mushroom grow kits reusable?
Sort of! While the kit itself isn’t designed to keep going forever, most people get 2 or 3 flushes (harvests) from a single block. After the first crop, just keep misting and give the kit a bit of time - it’ll often bounce back with a second (and sometimes even a third) wave.
Once the kit has given all it can, you can pop the spent block into the compost, use it as garden mulch, or even experiment with outdoor growing. Some customers report surprise mushrooms popping up in their gardens months later!
What are mushroom grow kits?
A mushroom grow kit is a ready-to-grow block of growing medium (called substrate), infused with mushroom mycelium - the root-like network that mushrooms grow from. Ours home kits come fully colonised, which means the hard part’s already done. All you have to do is open the box, follow the instructions, and give your kit the right conditions.
We’ve taken the complexity out of mushroom growing, so you don’t need lab gear or prior knowledge - just a misting bottle, some curiosity, and a little patience.
Can mushroom grow kits go bad?
Like any living product, mushroom kits do have a shelf life. If you leave one sitting unopened for months or store it in a warm cupboard, it might dry out or become less productive.
That said, our kits are fresh when shipped and usually happy for up to four weeks in the fridge if you’re not quite ready to start straight away. Once opened and activated, the block is alive and wants to grow - so give it some love (and moisture), and it’ll reward you soon enough.
Keep an eye out for signs of contamination (like green mould or strong off smells), and if in doubt, give us a shout - we’re always happy to help.
How do mushroom grow kits work?
It’s like nature in a box. Each grow kit is a living culture of mycelium that’s been growing quietly inside a block of organic substrate. When you open the kit and expose it to air, humidity and light you’re mimicking the conditions mushrooms experience in the wild - triggering them to fruit.
Oyster Mushrooms are especially quick off the mark and they can start forming within 5–7 days. Lion’s Mane is a bit slower and more mysterious, but worth the wait with its shaggy, white pom-poms and nutty flavour.
Our kits come with clear instructions and troubleshooting tips, but the basics are simple: cut, mist, and watch the magic happen.
How long do mushroom grow kits last?
Unopened, a grow kit can last four weeks if kept cool. Once opened, things move quickly. Most people see their first harvest within 7–21 days of activation.
You can expect multiple flushes over the course of 3–5 weeks, depending on the species, care, and your home environment. After that, the kit will gradually slow down. At that point, you can compost it, pop it in your garden, or even use it as a base for trying out DIY cultivation.
How to use mushroom grow kits?
Using our grow kits couldn’t be easier. Here’s a quick overview:
- Open the box and read the instructions.
- Cut an opening in the bag where indicated.
- Place the kit somewhere with indirect light and fresh air.
- Keep it moist by misting two times a day.
- Harvest once mushrooms are fully grown.
You don’t need special equipment and we’re always available via email or Instagram DM if you need help.
How to make mushroom grow kits?
If you're feeling adventurous, you can absolutely try making your own kits. It’s a great next step once you’ve mastered using a pre-made one. You’ll need mushroom spawn, a substrate (like straw or hardwood sawdust), and some basic knowledge of sterilisation and incubation.
It’s more involved, but also really rewarding. Our advice? Start with a kit, get a feel for how mushrooms grow, and then build your skills from there. And hey - if you ever want to branch out, we’ll be cheering you on (and might even have spawn kits in the pipeline...).
Ready to grow your own mushrooms?
Whether you’re after the brain-boosting benefits of Lion’s Mane or the quick, colourful yields of pink Oysters, we’ve got a grow kit for you.
All our kits are handmade in small batches, fully colonised, and ready to burst into life.
🌿 Browse our mushroom grow kits and start your fungi journey today.
And if you’ve still got questions, don’t hesitate to reach out—we’re always here to help fellow mushroom lovers grow something marvellous.
